What is a UTM link builder and why does spelling matter
A UTM link builder appends five standard parameters to a URL so Google Analytics can record where a click came from. The parameters are utm_source (the site or sender), utm_medium (the channel type), utm_campaign (the promotion), utm_term (the paid keyword) and utm_content (which link in the email or ad). GA4 reads them on the landing page and attributes the session, the conversions and the revenue to that campaign.
The reason to use a builder instead of typing the parameters by hand is consistency. GA4 is case sensitive and does not trim spaces, so Newsletter, newsletter and newsletter become three different sources in your reports. This free UTM generator lowercases the values, swaps spaces for underscores and URL-encodes anything else, so one campaign stays one row.
Which utm_medium values does GA4 recognise
GA4 assigns sessions to default channel groups by matching utm_medium and utm_source against a fixed list of rules. Some mediums map cleanly, others land in Unassigned unless you build a custom channel group.
| utm_medium | GA4 default channel | Typical use |
|---|
| email | Email | Newsletters, drips, transactional |
| cpc | Paid Search | Google Ads, Microsoft Ads |
| paid_social | Paid Social | Meta, LinkedIn, TikTok ads |
| social | Organic Social | Unpaid posts and bios |
| display | Display | Banner and programmatic |
| referral | Referral | Partner sites, listicles |
| affiliate | Affiliate | Affiliate programmes |
| sms | SMS | Text campaigns |
| qr, whatsapp, podcast | Unassigned | Add a custom channel group in GA4 |
The full matching rules are in Google's default channel group documentation, linked in the sources below.
Naming conventions that survive more than one campaign
- Lowercase everything. Decide once and never revisit it.
- Underscores, not spaces or hyphens. Hyphens work, but pick one and keep it.
- Source is the platform, medium is the channel type. utm_source=linkedin with utm_medium=paid_social is correct. utm_source=paid_social is not.
- Campaign names carry the date. spring_sale_2026 beats spring_sale, because you will run it again.
- Content distinguishes placements. hero_button versus footer_link tells you which link in the email did the work.
- Never tag internal links. A UTM on a link from your own homepage to your own pricing page overwrites the real source with a fake one.
Mistakes this builder catches
It warns when utm_source, utm_medium or utm_campaign is missing, because GA4 will file the session as direct or unassigned. It strips any utm_ parameters already on the URL so you do not end up with two sources on one link. It keeps existing non-UTM parameters intact. It moves the parameters in front of any #fragment, since anything after the hash never reaches the server or the analytics tag. And if you turn normalisation off, it flags capitals and spaces so you can see exactly what GA4 will receive.
Questions people ask
Do I need all five UTM parameters?
No. GA4 needs utm_source and utm_medium to attribute the session, and you need utm_campaign to tell campaigns apart. utm_term and utm_content are optional and mostly useful for paid search and for A/B testing links inside one email.
Does GA4 still use UTM parameters?
Yes. GA4 reads utm_source, utm_medium, utm_campaign, utm_term and utm_content, and adds utm_id, utm_source_platform, utm_creative_format and utm_marketing_tactic. This builder covers the five that every platform and report understands.
Why does my campaign show up twice in GA4?
Almost always a spelling difference. Newsletter and newsletter are two sources. A trailing space is a third. Use the normalise option here and keep a shared sheet of the exact values your team uses.
Should I use UTM links on Google Ads?
Usually not by hand. Google Ads auto-tagging adds a gclid that GA4 reads, and manual UTMs can conflict with it. Use UTMs for email, social, partners and anything Google Ads does not tag for you.
Can UTM parameters hurt SEO?
Only if the tagged URL gets indexed as a duplicate. Make sure the page has a canonical tag pointing at the clean URL, which most sites already do, and never put UTMs on internal links.
Is the tagged link shortened?
No. This builder returns the full URL so you can see every parameter. Shorten it in your link tool afterwards if the channel needs it; the parameters survive a redirect.
Sources
Last reviewed 14 September 2026. Formulas and benchmarks are published on the page so you can check them. This tool gives estimates, not quotes.
